Direct positive silver halide photographic photosensitive material

ABSTRACT

A direct positive silver halide photosensitive material containing in its silver halide emulsion layer and/or the adjacent layer(s) thereof (1) at least one sensitizing dye represented by the following general formula I:   wherein R and R&#39;&#39; are each an alkyl or a substituted alkyl group, L is a methine chain, Z represents the group of atoms necessary to form a five or six membered nitrogen-containing heterocyclic nucleus, X is an anion and n is 0 or 1, and (2) at least one water-soluble (high) polymer having repeating units represented by the following general formula II:   wherein R1 is H or CH3, R2 is -OH, -OCOR3, -COOR3, -CN, -CONH2, -CONHR3,   in which R3 and R4 each represents an alkyl group of from one to four carbon atoms and R5 represents H, CH3 or C2H5, and x is a positive number of from 50 to 100 representing the percentage ratio, is disclosed.

United States Patent [191 Kawano et al.

[ Nov. 6, I973 DIRECT POSITIVE SILVER I-IALIDE PI'IOTOGRAPI-IIC PHOTOSENSITIVE MATERIAL [75] Inventors: Hideo Kawano; I-Iirotetu Kato;

Nobuo Tsuji, all of Kanagawa, Japan [73] Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan [22] Filed: Apr. 27, 1971 [21] Appl. No.: 137,970

[51] Int. Cl G03c 1/14, G030 H72 [58] Field of Search 96/137, 135, 126, 96/l40, 114, 64

[56] References Cited UNITED STATES PATENTS 3,567,439 3/1971 Daniel et al. 96/101 Primary Examiner.l. Travis Brown Attorney-Sughrue, Rothwell, Mion, Zinn and Macpeak [57] ABSTRACT A direct positive silver halide photosensitive material containing in its silver halide emulsion layer and/or the adjacent layer(s) thereof (1) at least one sensitizing dye represented by the following general formula I:

Z CHr-CH CH2- I l tar/mt,

H. H H: H: (II) wherein R is H or CH R is -OH, -OCOR;,, -COOR -CN", -C ONH -CONHR in which R and R each represents an alkyl group of from one to four carbon atoms and R represents H, CH or C H and x is a positive number of from 50 to 100 representing the percentage ratio, is disclosed.

5 Claims, No Drawings BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a direct positive silver halide photographic photosensitive material. More particularly, this invention relates to a silver halide photographic photosensitive material from which a direct positive image having a high sensitivity to reversal and a low minimum density may be obtained using only one exposure and one developing treatment.

2. Description of the Prior Art In the art of manufacturing this kind of photographic photosensitive material, it is well known that the sensitivity to reversal is enhanced markedly by adding a desensitizer or a conventional sensitizing cyanine dye into an emulsion which has been previously fogged. As such desensitizers, there are known organic desensitizing dyes such as Pinacriptol Yellow and Pinacriptol Green or metals of the Group VIII of the Periodic Table, for example, as described in U. S. Pat. No. 2,717,833. Furthermore, as the aforesaid sensitizing dyes, conventional cyanine or merocyanine dyes are well known, for example, as described in Japanese Pat. application No. 4,125/68. However, these sensitizing dyes, when added, cause an increase in residual color density together with an increase in the sensitivity to reversal. The degree of the residual color density, of course, depends upon the type of sensitizing dye employed.

An object of the present invention is to prepare a direct positive silver halide photographic photosensitive material having a high sensitivity to reversal and no residual color density.

SUMMARY OF THE INVENTION wherein in the above formula R and R' each represents DETAILED DESCRIPTION OF THE INVENTION- Examples of the dyes represented by the abovedescribed general formula include liai e? h V a... 1- The water-soluble polymer or the water-soluble c0- polymer of N-vinylpyrrolidone to be employed together with the above-described dye is a (high) polymer having the repeating unit represented by the following general formula:

wherein in the above-described formula R is H or CH R is -OI'I, OCOR -COOR -CN, -CONH -CONI-IR I I Ra C ON Q, -III=COR5, --COOH or Q-sonzr, m which (Average molecular weight: Polyvinylpyrrolidone K-l5, manufactured by General Aniline & Film Corp.)

(Average molecular weight: l0,000).

Compound 4 (Average molecular weight: 30,000).

Compound 5 (Average molecular weight: 50,000).

Compound 6 (Average molecular weight: 100,000).

(Average molecular weight: 50,000).

Compound 8 (Average molecular weight: 20,000).

Compound 9 (Average molecular weight: 90,000).

Compound 10 (Average molecular weight: 80,000).

Compound 12 am-e19 em-ca (Average molecular weight: 150,000).

The silver halide photographic emulsion to which these sensitizing dyes and water-soluble (high) polymers are added may be prepared by dispersing silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver chloroiodide or silver chloroiodobromide into gelatin or a hydrophilic organic colloid as a protective colloid. The addition may be effected at any stage of the emulsion manufacturing process, but preferably from after completion of the formation of fogged nuclei to immediately before coating of the emulsion. The amounts to be employed depend upon the emulsion used, but it is preferred that the sensitizing dye be used in an amount of from 1 mg to 200 mg per mol silver halide and that the water-soluble-high polymer be employed in an amount of from 0.5 g to 50 g per mol silver halide. It is also possible to use either one kind of sensitizing dye or water-soluble high polymer, or a mixture of more than one kind of them.

In the present invention, any of known desensitizers such as Pinacriptol yellow and Phenosafranin may be employed together with the above-described compounds.

A direct positive silver halide photographic photosensitive material may be prepared by forming fogged nuclei in a silver halide emulsion obtained by conventional method of precipitation and physical ripening, by irradiation of the emulsion or by addition of a reducing agent such as formaldehyde, hydrazine and thiourea dioxide to the emulsion. Thereafter, the resulting emulsion is coated on a supporting material such as cellulose acetate film, polyethylene terephthalate film, baryta paper and synthetic paper with subsequent drying.

Furthermore conventional photographic additives such as hardening agents and surface active agents may also be added to the silver halide emulsion.

The direct positive silver halide photographic photosensitive materials are extremely excellent in that, as shown in the examples described hereinafter, they have a high sensitivity to reversal and no residual color density.

This invention is illustrated further in detail by reference to the following examples.

EXAMPLE 'l Into a percent aqueous gelatin solution were added simultaneously 500 cc of an aqueous solution containing 100 g of silver nitrate and 500 cc of an aqueous solution containing 6 g of sodium chloride and 70 g of potassium bromide and the reaction was carried out at a temperature of 50 C to form silver halide grains.

After the formation was complete, 1 g of potassium iodide and 40 g of gelatin were added and the pH was adjusted to 9.5 with sodium carbonate. Into this was added 5 ccof 1 percent hydrazine hydrochloride followed by ripening at a temperature of 50 C for 40 minutes to form fogged nuclei. Subsequent to the ripening, the pH was adjusted to 6.0 with 10 percent citric acid. After cooling and washing with water, Dye 2 and High Polymer 1 (Compound I) were added thereto in the amounts shown in Table 1.

For comparison, a sample using only Pinacriptol Yellow was prepared in the same manner.

TABLE 1 Amount of Compounds (g/mol Emulsion Pinakryptol No. Yellow Dye 2 Compound I Each of the above-described emulsions was separately coated on a cellulose triacetate film followed by drying.

The resulting direct positive silver halide photographic photosensitive material was exposed through an optical wedge to a tungsten lamp at 2,660 K and then developed for 3 minutes at C in a developer having the following composition. The sensitivity and residual color density of the resulting samples are summarized in Table 2.

Composition of the NOTE: The sensitivity ivss expressed as a specific sensitivity where the I sensitivity of the control sample was taken as 100.

The residual color density was expressed as transmission percentage at a wave length of 550 mg. of the part of the film after treatment having the minimum density, whereby the transmittance percentage of the control sample was taken as percent.

As is evident from the above-described Table 2, Samples No. 4 and 5 containing Dye 2 and Compound 2 of the present invention have markedly high sensitivity but little residual color density.

What is claimed is:

l. A direct positive silver halide photosensitive emulsion containing in its silver halide emulsion layer and/or the adjacent layer(s) thereof 1. at least one sensitizing dye represented by the folwherein R is selected from the group consisting of a hydrogen atom and a methyl group, R is selected from the group consisting of -OH, -OCOR -COOR -CN, -CONH -CONHR R4 CH:

wherein R and R are each an alkyl group having from one to four carbon atoms and wherein R 'is selected from the group consisting of a hydrogen atom, a methyl group and an ethyl group, and x is a positive percentage ranging from 50 to 100, inclusive.

2. The silver halide photosensitive emulsion of claiin 1, wherein said dye is selected from the group consisting of \C CH 53 A and all: 7H5 I and H50 CH5 KIT nmwcc H 10 (Jilly): 5 0a" Jlzlls I 3. The silver halide photosensitive emulsion of claim 2, wherein said high polymer is selected from the group consisting of:

N O OCH: N\ .ONH: Hzc \C=O H2O 0:0 Ha H2 1 H2 H2 4. The silver halide photosensitive emulsion of claim 1, wherein said sensitizing dye is present at a level of from 1 mg to 200 mg per mole of silver halide and wherein said high polymer has a molecular weight ranging from 5,000 to 500,000, and is present at a level of from 05 g to 50 g per mole of silver halide.

5. The silver halide photosensitive emulsion of claim 1, wherein R and R are selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isobutyl group, a [3 -sulfoethyl group, a y -sulfopropyl group, a B -methoxy-ethyl group, a B -hydroxyethyl group, and a carboxymethyl group. 

2. The silver halide photosensitive emulsion of claim 1, wherein said dye is selected from the group consisting of
 2. at least one water soluble high polymer having the repeating unit represented by the following general formula II;
 3. The silver halide photosensitive emulsion of claim 2, wherein said high polymer is selected from the group consisting of:
 4. The silver halide photosensitive emulsion of claim 1, wherein said sensitizing dye is present at a level of from 1 mg to 200 mg per mole of silver halide and wherein said high polymer has a molecular weight ranging from 5,000 to 500,000, and is present at a level of from 0.5 g to 50 g per mole of silver halide.
 5. The silver halide photosensitive emulsion of claim 1, wherein R and R'' are selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an isobutyl group, a Beta -sulfoethyl group, a gamma -sulfopropyl group, a Beta -methoxy-ethyl group, a Beta -hydroxyethyl group, and a carboxymethyl group. 